For example, JP-A-2001-350307 describes a related art image forming apparatus that forms an image electrophotograpically, in which a plurality of photosensitive cartridges are arranged in parallel along a predetermined direction.
In each photosensitive cartridge, a cartridge frame body houses a photosensitive drum on which an electrostatic latent image is formed, a charger which charges the photosensitive drum, and a developing unit which develops the electrostatic latent image.